package edu.chl.jadetalk.servlets;

import edu.chl.jadetalk.business.upload.ImageDataManagerBeanLocal;
import java.io.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Serves images from the FTP server (or cache) on the /image/[image_name] url pattern.
 * @author Erik
 */
public class ImageServlet extends HttpServlet {
    
    @EJB
    private ImageDataManagerBeanLocal imageManagerBean;

    /**
     * Processes requests for both HTTP
     * <code>GET</code> and
     * <code>POST</code> methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String imageName = request.getPathInfo().substring(1);

        InputStream input = null;
        OutputStream output = null;

        try {
            
            // Get image from ftp
            byte[] image = imageManagerBean.getImage(imageName);

            // Set response
            response.setHeader("Content-Type", getServletContext().getMimeType(imageName));
            response.setHeader("Content-Length", String.valueOf(image.length));

            input = new BufferedInputStream(new ByteArrayInputStream(image));
            output = new BufferedOutputStream(response.getOutputStream());
            
            byte[] buffer = new byte[8192];
            int length;
            while ((length = input.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
            
        }
        catch(Exception e){
            Logger.getAnonymousLogger().log(Level.SEVERE, "Exception during image read: " + e.getMessage());
            //response.sendError(404, e.getMessage());
        }
        finally {
            if (output != null) {
                try {
                    output.close();
                }
                catch (Exception e) {}
            }
            if (input != null) {
                try {
                    input.close();
                }
                catch (Exception e) {}
            }
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
